High-intensity flaming-arc lamp



y 7, 1929- P. R. BASSETT 1,711,983

HIGH INTENSITY FLAMING' ARC LAMP Filed June 14, leis 2 Sheets-Sheet l I2 I I Winn. 25 22 INVENTOR 19/755 m/v REmssm y 1929- P. R. BASSETT 1,711,983

HIGH INTENSITY FLAMING ARC LAMP Filed June 14, 1918 2 sheets sheet 2 wil INVENTOR flan /15,455 577: F Jv f/bmiw Patented May 7, 1929.

UNITED STATES PATENT OFFICE.

PRESTON B. BASSETT, OF BROOKLYN, NEW YORK, ASSIGNOR, BY MESNE ASSIGN- MENTS, TO THE SPERBY GYBOSCOPE COMPANY, INC., A CORPORATION 01' m YORK.

Application filed June 14,

This invention relates to high intensity flaming arc lights, having especial reference to searchlights.

The principal objects of the invention are to simplify and to improve the construction of such lampswhereby steady operation is obtained irres ective of the positon of the light; or in t er words, whether it is right side up, up side down, or on end.

, A further object is to secure proper burning conditions with a minimum number of parts and to simplify the ventilation of such lamps.

Referring to the drawings in which, what is now considered the preferred forms of my invention, are illustrated:

Fig. 1 is a view of the lamp partly in section, as it appears within the Searchlight drum.

Fig. 2 is a section through the Searchlight drum looking toward the front door.

Fig. 3 is a cross section taken approximate 1y on line 3-3 of Fig.1.

Fig. 1 is a sectional view showing a mod:

- ification in the manner in which the current is led to the arc, the lam also bein shown in the inverted position rom that shown in Figs. 1 and 2. V

Fig. 5 is a side view of the holders, constructed according to said modification.

Fig.1 is a section of a modified form of Searchlight having little or no drum and no front door.

As is now usual in searchlights, I have shown the lamp proper mounted on a control box 1, which is slidably mounted in the base of the drum 2. Rising from said box is a standard 3 preferably of hollow construction and elliptical or elongated cross section. To said standard is secured the holder 1 for the positive electrode 5. Said standard alsopreferably supports the holder 6 for the negative electrode 7. As shown the positive holder is insulated by fireproof insulation 8 from the standard; the current being introduced to the holder by a wire 9. The negative holder is also shown as bolted to the positive holder at 10 and insulated therefrom; the current to the negative holder being introduced by wire 11. A bar 12 which leads the current to the negative holder is shown as supporting it from the positive holder and passing over the top of the holders. Preferably both electrodes are rotated and fed within their re- 1918. Serial No. 239,927.

spective holders by any' suitable mechanism which forms ngfirt of this invention. For rotating and fe g the positive electrode an osc1llatory intermittent gripping mechanism 13 is illustrated. Said mechanism is 0 rated from the shaft 14 in the control box t ough a crank shaft 15 and link 16,. The rate of feed is controlled by adjusting the angle of the member 17 which controls the advance of the gripping means during its oscillation.

As said mechanism forms no part of thisinvention, and is completely described in a copending application of Theodore Hall, Serial No. 235,7 7 1, filed May 21, 1918, for gearless feeding and rotating mechanism for electrodes, of which The Sperry Gyroscope Company, the assignee of the present invention, is the owner, no further details need be presented.

Spring ressed brushes 18 and 19 may also be provi ed, said brushes being p against the electrode by spring 20 connected thereto through linkage 21. Near the for ward end of the holder comparatively large cooling ribs 22 are shown. The said shields or ribs are shown as secured together by bolts 24. To said ribs are secured a forwardly ex tending refractory sleeve 23 adapted to shield the positive electrode up to a point a predetermined distance back of the electrode tip. A comparatively large housing 25 which may or may not be formed as a part of said ribs is so placed as to enclose on substantially three sides the arcing faces of the electrodes with the opening side facing the mirror, a portion of which is represented at 39. Said housing and preferably also substantially all parts of the holders are formed of non-magnetic material. The housing is shown as secured to the standard 3 and may be provided with an opening 26 at the back. Preferably the opening in the top of the standard extends some distance behind the shield 25 as shown in Fig. 3 so that air is also drawn down over the cooling ribs 22. The negative hold er is also shown as provided with spring pressed brushes 18', held in place b spring 20. The feeding mechanism is s own as comprising feed rollers 28 which are actuated by the shaft 29 leading to the control box. The mechanism for turning the shaft 29 is represented as enclosed within the box 30 and may be of any standard t e of mechanism for feeding an electrode y voltage control or otherwise. A knurled knob 31 is shown for actuating the feed manually if desired.

Within the control box an electric motor 32 is shown for actuating the feeding and rotatin means. Said motor is shown as provide witha pinion 33 meshing with the gear 34 on said shaft 14. The motor shaft 35 passes through a centrifugal blower or other air exhausting means 36, the said shaft serving to operate said blower. A sectlon of the drum 2 1s roughly illustrated in Fig. 1 and a portion of the mirror is shown at 39; the mirror being of the usual type as shown more clearly in Fig. 6..

The Searchlight as a whole is shown as mounted in trunnion arms 4041 on a rotatable base 42. In Fig. 2 the dotted lines represent the position of the light when it is inverted as frequently happens in following aircraft with a Searchlight.

It should be noted that the current passing through the bar 12 travels in the opposite direction from the current passing through the arc. Since very heavy currents are employed in this type of light, preferably 150 amperes or more, I have found that by this simple means a marked deflecting effect may be produced upon the arc flames. It should be further noted that the electrodes are positioned at an angle, the apex of which is directed away from the current carrying member 12. An arc of this character in which electrodes are positioned at an angle, operates substantially as outlined in the patent to Elmer A. Sperry, No. 1,227,210, May 22, 1917, according to which a brushing contact by the negative flame across the mouth of the positive crater is effected. I prefer however combining the above feature with said meth- 0d of operating as outlined therein whereby the operation of the arc is assured in all positions of the Searchlight. The operation of the form of invention described is as follows:

The exhaust blower 36 creates a continuous downward current of air through the standard 3 thereby continuously withdrawing the air and fumes from within the shield 25. Air may be admitted to the drum at any suitable location. i A ventilating hood with apertures 71 therein is shown for this purpose. As the electrodes are positioned at an angle the arc flames naturall curve toward the said opening as outlined 1n the said Elmer A. Sperry, especially if the electrodes are in the inverted position from that shown in Fig. 1; i. e., in the dotted line osition shown in Fig. 2. In the normal position of the lamp shown in Fi 1 and 2 with the tail flame lying underneat the crater of the sitive electrode, the downward draft 0 air created by the exhaust blower on the flame assists in maintaining the proper burning conditions for the high intensity are by repatent to placing the normal upward draft of air due to convection currents on the standard hi h intensity are. This inverted position of t e tail flame has an advantage in searchlights since in the ordinary high intensity are the image of the tail flame illuminates the foreground (as the reflector inverts the ima e), while according to m invention the illunnnation from the tail ame appears above the main beam and, therefore, it does not illuminate the foreground. Since the standard or chimne 3 extends close to the tip of the flame so produced, the downward current of air carries off immediately the fumes through the standard; while side deflecting currents of air are prevented b the shield. The opening 26 in the back 0 the shield assures a parallel movement of air from the top of the shield toward the bottom so as not to deflect the arc flames. In addition the repelling influence of the oppositely traveling current through bar 12 aids in steadying the are in directing it toward the said outlet irres tive of the position of the Searchlight and ix i assuring the proper brushing contact under all conditions.

In Figs. 4 and 5 the holders are substantiall of the same form except that additional con uctors are placed near the arc whereby a further deflection is secured. According to this modification the negative holder 6' is placed substantiall parallel to the positive holder 4, but slight y out of line with the same, the negative holder being sli htly nearer the repelling conductors than t e positive holder. The current to the ositive holder is shown as introduced throng the insulated wire 46 which is supported to one side above the top of the holders; thence downwardly; thence parallel to the holders, the wire being shown as supported by the bar 12; thence upwardly and into the positive holder. The wire to the negative electrode is shown at 47 and leads first to one side and over the holders, thence downwardly where it is secured to the bar 12. The direction of the. arrows show the direction of the'current passing through the wires and through the arc, the arrows 50 showing the direction of the current through the positive leadin -in wire while the arrows 51 show the direction of current in the negative leadin -in wires.

In the above it will be seen t at theplurality of conductors through which the current travels in the opposite direction to that through-the are are closely positioned and placed to that side of the are away from the exhaust opening; while the plurality of conductors through the same direction as that through the arc are positioned adjacent but spaced to either side of said opening. By this means a very powerful deflecting influence is exerted on the arc, since, according to the well known laws of attraction and repulsion the first menwhich the current passes in by air currents. Also b spacing the conductors which attract the aine so that the flame will pass between rather than toward either conductor, the damaging effect of the heat from the flame is avoided, the heat being led directly up the chimney 3. In this form of arc in order to secure the coaction of the negative flame with the positive flame as outlined in the aforementioned patent of Elmer A. Sperry, I find it preferable to position the negative electrode slightly nearer the repelling conductors as outlined above, so that a brushing contact across the mouth of the positive may be secured.

In employing an arc of this character I find it unnecessary to employ a drum for enclosing the mechanism of the arc, since sufficient steadiness may be obtained by the methods outlined herein without shutting off all air currents. Furthermore by burning the are more or less in the openthe problem of removing the fumes is less serious, the weight of the light is reduced, and the front door rendered unnecessary. Such a lamp is illustrated roughly in Fig. 6 wherein a skeleton drum of only suflicient depth to cut oii stray light from the crater 51 of the positive electrode is shown. The said drum is pivoted on trunnions 52 in any suitable manner and supports the mirror 53. The electrode holders 4- and 6" are shown as supported from the drum by a tripod having two similar legs 54, one of which is cut away in Fig. 6, and a third hollow leg 55. Said leg55 may perform all 'ofthe functions of the standard 3 in the preferred form of the invention. The exhaust motor 32' and blower 36 are shown at the base of said leg 55.- Shaft 16' is shown for rotating and feeding the positive electrode while the shaft 29' is shown for feeding the negative electrode. As hood 25' encloses the are on three sides, it also serves, in this form of the invention, to cut oil all light from the arc except that striking the pro ector 53. v

In this form of the invention the construction of the holders may be similar to either of the structures heretofore outlined. In the construction shown the holders are provided of, but I desire to have it understood that the apparatus shown is only illustrative and that the invention can be carried out by other with the axes of the means. Also, while it is designed to use the various features and elements in the combination and relations described, some of these may be altered and others omitted without in.- terfering with the more general results outllned, and the invention extends to such use.

IfIavin described my invention, what I claim an desire to secure by Letters Patent is:

1. In a Searchlight, the combination with a drum, ofa lurality of electrode holders, a hollow stan ard extending within said drum and supporting one of said holders with the axis of the electrode at a substantial angle to the standard, said standard having an intake for receiving the arc gases, and means for withdrawin a1r through saidstandard.

2.. In a search ight, the combination with a supporting frame, of a plurality of electrode ho ders, a hollow standard supported by said frame and sup rtin said electrode holders edectrodes at substantial angles to the holders, said standard having an intake adjacent said holders for receiving the arc gases and means for withdrawing air through said standard.

3. In a flaming are lamp, a pair of electrode holders. a current-carrying conductor to one side of the holders for causing deflection of the arc flames in a predetermined direction, and means adjacent the are for conducting air from the lamp in the direction of such deflection- 4.'In a flaming arc lamp, a pair of electrode holders, a current-carryin conductor to one side of the position adapte to be occus arc flames in a predetermined direction, and a chimney having an intake adjacent the position of the are and placed in line with said direction of deflection.

pied by the are for causing deflection of the 5. In a flaming arc lamp, a pair of electrode holders,a current-carrying conductor so positioned as to lie to one side of the are for causing deflection of the arc flames in a predetermined direction, a chimney having an intake so positioned as to lie adjacent the arc and placed in line with said direction of deflection, and means for creating an outward draft through said chimney.

6. In a flaming arc li ht, the combination with a pair of electro es positioned at an angle to one another whereby the resultant arc flame sweeps toward the apex of said angle irrespective of the position of the lamp, and an outlet opening positioned beyond the apex of said an le.

7. In a search ight, an upwardly extending, hollow supporting standard, an electrode holder supported on either side of said standard, said standard having an opening to receive the are fumes and means for creating a downward draft through said standard.

8. In a flaming are light, the combination with a pair of electrodes positioned at an angle to-one another, with the a ex of said angle facing substantially ownwardly whereb the resultant are tall flame tends to therethrough whereby a downward draft of air is created on said-arc.

9. The combination with a Searchlight, of a control box, a hollow standard on said box, electrode holders supported on said standard, and an exhaust bl wer located in said box for ventilating t e searchlight through said standard.

10. In a searchlight, the combination with a pair of electrode holders, of an electrical conductor positioned substantially parallel so that it to one side of said holders and means ad'acent the opposite side of said holders or withdrawing the air adjacent said holders.

11. In a Searchlight, the combination with a positive and a negative electrode holder, of an electrical conductor adjacent one side of said holders and adapted to carry a current substantially parallel to said holders in a direction running from said negative holder to said positive holder and means adjacent the opposite side of said holders for exhaust ing the air between said holders.

12. The combination with a searehlight, of an electrode holder therein, cooling ribs on said holder, a hollow standard extending transversely into said Searchlight and supporting said holder and having an intake opening adjacent said ribs, and an exhaust blower for withdrawing air through said standard, whereb a circulation of air over said ribs is caused? 13. In a flaming arc searchlight, the com bination with the electrodes, of a reflector, means for supporting the positive electrode points towards said reflector, a hood enclosing the space adapted to be occupied by the are on all sides except the side nearest to said reflector to cut off stray light and means for withdrawing air from said hood.

14. In a Searchlight, the combination with upon which one of said electrodes is mounted, an arm supported by said standard and carrying the other electrode, said s'tandardhaving an opening adjacent the space adapted to be occupied by the arc, and means for causing a downward flow of air through said standard away from such space.

16. In a Searchlight, the combination with a pair of electrodes, of a hollow standard u on which one of said electrodes is mounte at a substantial angle thereto, a current conducting arm along which current isadapted to pass to the other of said electrodes, said arm being supported by said standard and carrying said other electrode andmeans for causing a flow of air through said standard.

17. In a flaming arc Searchlight, the combination with the electrodes, of a reflector, means for supporting the ositive electrode so that it points toward sai reflector, a hood enclosing the space adapted to be occupied by the are on all sides except the side nearest to the reflector to cut oil stray light, said hood having an opening on one side thereof, means for withdrawing air through said opening, and means for deflecting the arc flames towards said opening.

18. In a flaming arc Searchlight, the combination with the electrodes, of a reflector, means for supporting the positive electrode so that it points toward said reflector, a hood enclosing the space adapted to be occupied by the are on all sides except the side nearest to the reflector to cut off stray light, said hood having an opening -on'one side thereof, and means for withdrawing air through said opening, including a duct leading without the beam and an exhaust fan connected thereto.

In testimony whereof I have aflixed my signature.

PRESTON R. BASSETT. 

